1 // SPDX-License-Identifier: GPL-2.0-only
3 * Persistent Memory Driver
5 * Copyright (c) 2014-2015, Intel Corporation.
6 * Copyright (c) 2015, Christoph Hellwig <hch@lst.de>.
7 * Copyright (c) 2015, Boaz Harrosh <boaz@plexistor.com>.
10 #include <asm/cacheflush.h>
11 #include <linux/blkdev.h>
12 #include <linux/hdreg.h>
13 #include <linux/init.h>
14 #include <linux/platform_device.h>
15 #include <linux/set_memory.h>
16 #include <linux/module.h>
17 #include <linux/moduleparam.h>
18 #include <linux/badblocks.h>
19 #include <linux/memremap.h>
20 #include <linux/vmalloc.h>
21 #include <linux/blk-mq.h>
22 #include <linux/pfn_t.h>
23 #include <linux/slab.h>
24 #include <linux/uio.h>
25 #include <linux/dax.h>
27 #include <linux/backing-dev.h>
32 static struct device
*to_dev(struct pmem_device
*pmem
)
35 * nvdimm bus services need a 'dev' parameter, and we record the device
41 static struct nd_region
*to_region(struct pmem_device
*pmem
)
43 return to_nd_region(to_dev(pmem
)->parent
);
46 static void hwpoison_clear(struct pmem_device
*pmem
,
47 phys_addr_t phys
, unsigned int len
)
49 unsigned long pfn_start
, pfn_end
, pfn
;
51 /* only pmem in the linear map supports HWPoison */
52 if (is_vmalloc_addr(pmem
->virt_addr
))
55 pfn_start
= PHYS_PFN(phys
);
56 pfn_end
= pfn_start
+ PHYS_PFN(len
);
57 for (pfn
= pfn_start
; pfn
< pfn_end
; pfn
++) {
58 struct page
*page
= pfn_to_page(pfn
);
61 * Note, no need to hold a get_dev_pagemap() reference
62 * here since we're in the driver I/O path and
63 * outstanding I/O requests pin the dev_pagemap.
65 if (test_and_clear_pmem_poison(page
))
66 clear_mce_nospec(pfn
);
70 static blk_status_t
pmem_clear_poison(struct pmem_device
*pmem
,
71 phys_addr_t offset
, unsigned int len
)
73 struct device
*dev
= to_dev(pmem
);
76 blk_status_t rc
= BLK_STS_OK
;
78 sector
= (offset
- pmem
->data_offset
) / 512;
80 cleared
= nvdimm_clear_poison(dev
, pmem
->phys_addr
+ offset
, len
);
83 if (cleared
> 0 && cleared
/ 512) {
84 hwpoison_clear(pmem
, pmem
->phys_addr
+ offset
, cleared
);
86 dev_dbg(dev
, "%#llx clear %ld sector%s\n",
87 (unsigned long long) sector
, cleared
,
88 cleared
> 1 ? "s" : "");
89 badblocks_clear(&pmem
->bb
, sector
, cleared
);
91 sysfs_notify_dirent(pmem
->bb_state
);
94 arch_invalidate_pmem(pmem
->virt_addr
+ offset
, len
);
99 static void write_pmem(void *pmem_addr
, struct page
*page
,
100 unsigned int off
, unsigned int len
)
106 mem
= kmap_atomic(page
);
107 chunk
= min_t(unsigned int, len
, PAGE_SIZE
- off
);
108 memcpy_flushcache(pmem_addr
, mem
+ off
, chunk
);
117 static blk_status_t
read_pmem(struct page
*page
, unsigned int off
,
118 void *pmem_addr
, unsigned int len
)
125 mem
= kmap_atomic(page
);
126 chunk
= min_t(unsigned int, len
, PAGE_SIZE
- off
);
127 rem
= memcpy_mcsafe(mem
+ off
, pmem_addr
, chunk
);
130 return BLK_STS_IOERR
;
139 static blk_status_t
pmem_do_read(struct pmem_device
*pmem
,
140 struct page
*page
, unsigned int page_off
,
141 sector_t sector
, unsigned int len
)
144 phys_addr_t pmem_off
= sector
* 512 + pmem
->data_offset
;
145 void *pmem_addr
= pmem
->virt_addr
+ pmem_off
;
147 if (unlikely(is_bad_pmem(&pmem
->bb
, sector
, len
)))
148 return BLK_STS_IOERR
;
150 rc
= read_pmem(page
, page_off
, pmem_addr
, len
);
151 flush_dcache_page(page
);
155 static blk_status_t
pmem_do_write(struct pmem_device
*pmem
,
156 struct page
*page
, unsigned int page_off
,
157 sector_t sector
, unsigned int len
)
159 blk_status_t rc
= BLK_STS_OK
;
160 bool bad_pmem
= false;
161 phys_addr_t pmem_off
= sector
* 512 + pmem
->data_offset
;
162 void *pmem_addr
= pmem
->virt_addr
+ pmem_off
;
164 if (unlikely(is_bad_pmem(&pmem
->bb
, sector
, len
)))
168 * Note that we write the data both before and after
169 * clearing poison. The write before clear poison
170 * handles situations where the latest written data is
171 * preserved and the clear poison operation simply marks
172 * the address range as valid without changing the data.
173 * In this case application software can assume that an
174 * interrupted write will either return the new good
177 * However, if pmem_clear_poison() leaves the data in an
178 * indeterminate state we need to perform the write
179 * after clear poison.
181 flush_dcache_page(page
);
182 write_pmem(pmem_addr
, page
, page_off
, len
);
183 if (unlikely(bad_pmem
)) {
184 rc
= pmem_clear_poison(pmem
, pmem_off
, len
);
185 write_pmem(pmem_addr
, page
, page_off
, len
);
191 static blk_qc_t
pmem_make_request(struct request_queue
*q
, struct bio
*bio
)
198 struct bvec_iter iter
;
199 struct pmem_device
*pmem
= q
->queuedata
;
200 struct nd_region
*nd_region
= to_region(pmem
);
202 if (bio
->bi_opf
& REQ_PREFLUSH
)
203 ret
= nvdimm_flush(nd_region
, bio
);
205 do_acct
= nd_iostat_start(bio
, &start
);
206 bio_for_each_segment(bvec
, bio
, iter
) {
207 if (op_is_write(bio_op(bio
)))
208 rc
= pmem_do_write(pmem
, bvec
.bv_page
, bvec
.bv_offset
,
209 iter
.bi_sector
, bvec
.bv_len
);
211 rc
= pmem_do_read(pmem
, bvec
.bv_page
, bvec
.bv_offset
,
212 iter
.bi_sector
, bvec
.bv_len
);
219 nd_iostat_end(bio
, start
);
221 if (bio
->bi_opf
& REQ_FUA
)
222 ret
= nvdimm_flush(nd_region
, bio
);
225 bio
->bi_status
= errno_to_blk_status(ret
);
228 return BLK_QC_T_NONE
;
231 static int pmem_rw_page(struct block_device
*bdev
, sector_t sector
,
232 struct page
*page
, unsigned int op
)
234 struct pmem_device
*pmem
= bdev
->bd_queue
->queuedata
;
238 rc
= pmem_do_write(pmem
, page
, 0, sector
,
239 hpage_nr_pages(page
) * PAGE_SIZE
);
241 rc
= pmem_do_read(pmem
, page
, 0, sector
,
242 hpage_nr_pages(page
) * PAGE_SIZE
);
244 * The ->rw_page interface is subtle and tricky. The core
245 * retries on any error, so we can only invoke page_endio() in
246 * the successful completion case. Otherwise, we'll see crashes
247 * caused by double completion.
250 page_endio(page
, op_is_write(op
), 0);
252 return blk_status_to_errno(rc
);
255 /* see "strong" declaration in tools/testing/nvdimm/pmem-dax.c */
256 __weak
long __pmem_direct_access(struct pmem_device
*pmem
, pgoff_t pgoff
,
257 long nr_pages
, void **kaddr
, pfn_t
*pfn
)
259 resource_size_t offset
= PFN_PHYS(pgoff
) + pmem
->data_offset
;
261 if (unlikely(is_bad_pmem(&pmem
->bb
, PFN_PHYS(pgoff
) / 512,
262 PFN_PHYS(nr_pages
))))
266 *kaddr
= pmem
->virt_addr
+ offset
;
268 *pfn
= phys_to_pfn_t(pmem
->phys_addr
+ offset
, pmem
->pfn_flags
);
271 * If badblocks are present, limit known good range to the
274 if (unlikely(pmem
->bb
.count
))
276 return PHYS_PFN(pmem
->size
- pmem
->pfn_pad
- offset
);
279 static const struct block_device_operations pmem_fops
= {
280 .owner
= THIS_MODULE
,
281 .rw_page
= pmem_rw_page
,
282 .revalidate_disk
= nvdimm_revalidate_disk
,
285 static int pmem_dax_zero_page_range(struct dax_device
*dax_dev
, pgoff_t pgoff
,
288 struct pmem_device
*pmem
= dax_get_private(dax_dev
);
290 return blk_status_to_errno(pmem_do_write(pmem
, ZERO_PAGE(0), 0,
291 PFN_PHYS(pgoff
) >> SECTOR_SHIFT
,
295 static long pmem_dax_direct_access(struct dax_device
*dax_dev
,
296 pgoff_t pgoff
, long nr_pages
, void **kaddr
, pfn_t
*pfn
)
298 struct pmem_device
*pmem
= dax_get_private(dax_dev
);
300 return __pmem_direct_access(pmem
, pgoff
, nr_pages
, kaddr
, pfn
);
304 * Use the 'no check' versions of copy_from_iter_flushcache() and
305 * copy_to_iter_mcsafe() to bypass HARDENED_USERCOPY overhead. Bounds
306 * checking, both file offset and device offset, is handled by
309 static size_t pmem_copy_from_iter(struct dax_device
*dax_dev
, pgoff_t pgoff
,
310 void *addr
, size_t bytes
, struct iov_iter
*i
)
312 return _copy_from_iter_flushcache(addr
, bytes
, i
);
315 static size_t pmem_copy_to_iter(struct dax_device
*dax_dev
, pgoff_t pgoff
,
316 void *addr
, size_t bytes
, struct iov_iter
*i
)
318 return _copy_to_iter_mcsafe(addr
, bytes
, i
);
321 static const struct dax_operations pmem_dax_ops
= {
322 .direct_access
= pmem_dax_direct_access
,
323 .dax_supported
= generic_fsdax_supported
,
324 .copy_from_iter
= pmem_copy_from_iter
,
325 .copy_to_iter
= pmem_copy_to_iter
,
326 .zero_page_range
= pmem_dax_zero_page_range
,
329 static const struct attribute_group
*pmem_attribute_groups
[] = {
330 &dax_attribute_group
,
334 static void pmem_pagemap_cleanup(struct dev_pagemap
*pgmap
)
336 struct request_queue
*q
=
337 container_of(pgmap
->ref
, struct request_queue
, q_usage_counter
);
339 blk_cleanup_queue(q
);
342 static void pmem_release_queue(void *pgmap
)
344 pmem_pagemap_cleanup(pgmap
);
347 static void pmem_pagemap_kill(struct dev_pagemap
*pgmap
)
349 struct request_queue
*q
=
350 container_of(pgmap
->ref
, struct request_queue
, q_usage_counter
);
352 blk_freeze_queue_start(q
);
355 static void pmem_release_disk(void *__pmem
)
357 struct pmem_device
*pmem
= __pmem
;
359 kill_dax(pmem
->dax_dev
);
360 put_dax(pmem
->dax_dev
);
361 del_gendisk(pmem
->disk
);
362 put_disk(pmem
->disk
);
365 static const struct dev_pagemap_ops fsdax_pagemap_ops
= {
366 .kill
= pmem_pagemap_kill
,
367 .cleanup
= pmem_pagemap_cleanup
,
370 static int pmem_attach_disk(struct device
*dev
,
371 struct nd_namespace_common
*ndns
)
373 struct nd_namespace_io
*nsio
= to_nd_namespace_io(&ndns
->dev
);
374 struct nd_region
*nd_region
= to_nd_region(dev
->parent
);
375 int nid
= dev_to_node(dev
), fua
;
376 struct resource
*res
= &nsio
->res
;
377 struct resource bb_res
;
378 struct nd_pfn
*nd_pfn
= NULL
;
379 struct dax_device
*dax_dev
;
380 struct nd_pfn_sb
*pfn_sb
;
381 struct pmem_device
*pmem
;
382 struct request_queue
*q
;
383 struct device
*gendev
;
384 struct gendisk
*disk
;
387 unsigned long flags
= 0UL;
389 pmem
= devm_kzalloc(dev
, sizeof(*pmem
), GFP_KERNEL
);
393 rc
= devm_namespace_enable(dev
, ndns
, nd_info_block_reserve());
397 /* while nsio_rw_bytes is active, parse a pfn info block if present */
398 if (is_nd_pfn(dev
)) {
399 nd_pfn
= to_nd_pfn(dev
);
400 rc
= nvdimm_setup_pfn(nd_pfn
, &pmem
->pgmap
);
405 /* we're attaching a block device, disable raw namespace access */
406 devm_namespace_disable(dev
, ndns
);
408 dev_set_drvdata(dev
, pmem
);
409 pmem
->phys_addr
= res
->start
;
410 pmem
->size
= resource_size(res
);
411 fua
= nvdimm_has_flush(nd_region
);
412 if (!IS_ENABLED(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
) || fua
< 0) {
413 dev_warn(dev
, "unable to guarantee persistence of writes\n");
417 if (!devm_request_mem_region(dev
, res
->start
, resource_size(res
),
418 dev_name(&ndns
->dev
))) {
419 dev_warn(dev
, "could not reserve region %pR\n", res
);
423 q
= blk_alloc_queue(pmem_make_request
, dev_to_node(dev
));
427 pmem
->pfn_flags
= PFN_DEV
;
428 pmem
->pgmap
.ref
= &q
->q_usage_counter
;
429 if (is_nd_pfn(dev
)) {
430 pmem
->pgmap
.type
= MEMORY_DEVICE_FS_DAX
;
431 pmem
->pgmap
.ops
= &fsdax_pagemap_ops
;
432 addr
= devm_memremap_pages(dev
, &pmem
->pgmap
);
433 pfn_sb
= nd_pfn
->pfn_sb
;
434 pmem
->data_offset
= le64_to_cpu(pfn_sb
->dataoff
);
435 pmem
->pfn_pad
= resource_size(res
) -
436 resource_size(&pmem
->pgmap
.res
);
437 pmem
->pfn_flags
|= PFN_MAP
;
438 memcpy(&bb_res
, &pmem
->pgmap
.res
, sizeof(bb_res
));
439 bb_res
.start
+= pmem
->data_offset
;
440 } else if (pmem_should_map_pages(dev
)) {
441 memcpy(&pmem
->pgmap
.res
, &nsio
->res
, sizeof(pmem
->pgmap
.res
));
442 pmem
->pgmap
.type
= MEMORY_DEVICE_FS_DAX
;
443 pmem
->pgmap
.ops
= &fsdax_pagemap_ops
;
444 addr
= devm_memremap_pages(dev
, &pmem
->pgmap
);
445 pmem
->pfn_flags
|= PFN_MAP
;
446 memcpy(&bb_res
, &pmem
->pgmap
.res
, sizeof(bb_res
));
448 if (devm_add_action_or_reset(dev
, pmem_release_queue
,
451 addr
= devm_memremap(dev
, pmem
->phys_addr
,
452 pmem
->size
, ARCH_MEMREMAP_PMEM
);
453 memcpy(&bb_res
, &nsio
->res
, sizeof(bb_res
));
457 return PTR_ERR(addr
);
458 pmem
->virt_addr
= addr
;
460 blk_queue_write_cache(q
, true, fua
);
461 blk_queue_physical_block_size(q
, PAGE_SIZE
);
462 blk_queue_logical_block_size(q
, pmem_sector_size(ndns
));
463 blk_queue_max_hw_sectors(q
, UINT_MAX
);
464 blk_queue_flag_set(QUEUE_FLAG_NONROT
, q
);
465 if (pmem
->pfn_flags
& PFN_MAP
)
466 blk_queue_flag_set(QUEUE_FLAG_DAX
, q
);
469 disk
= alloc_disk_node(0, nid
);
474 disk
->fops
= &pmem_fops
;
476 disk
->flags
= GENHD_FL_EXT_DEVT
;
477 disk
->queue
->backing_dev_info
->capabilities
|= BDI_CAP_SYNCHRONOUS_IO
;
478 nvdimm_namespace_disk_name(ndns
, disk
->disk_name
);
479 set_capacity(disk
, (pmem
->size
- pmem
->pfn_pad
- pmem
->data_offset
)
481 if (devm_init_badblocks(dev
, &pmem
->bb
))
483 nvdimm_badblocks_populate(nd_region
, &pmem
->bb
, &bb_res
);
484 disk
->bb
= &pmem
->bb
;
486 if (is_nvdimm_sync(nd_region
))
487 flags
= DAXDEV_F_SYNC
;
488 dax_dev
= alloc_dax(pmem
, disk
->disk_name
, &pmem_dax_ops
, flags
);
489 if (IS_ERR(dax_dev
)) {
491 return PTR_ERR(dax_dev
);
493 dax_write_cache(dax_dev
, nvdimm_has_cache(nd_region
));
494 pmem
->dax_dev
= dax_dev
;
495 gendev
= disk_to_dev(disk
);
496 gendev
->groups
= pmem_attribute_groups
;
498 device_add_disk(dev
, disk
, NULL
);
499 if (devm_add_action_or_reset(dev
, pmem_release_disk
, pmem
))
502 revalidate_disk(disk
);
504 pmem
->bb_state
= sysfs_get_dirent(disk_to_dev(disk
)->kobj
.sd
,
507 dev_warn(dev
, "'badblocks' notification disabled\n");
512 static int nd_pmem_probe(struct device
*dev
)
515 struct nd_namespace_common
*ndns
;
517 ndns
= nvdimm_namespace_common_probe(dev
);
519 return PTR_ERR(ndns
);
522 return nvdimm_namespace_attach_btt(ndns
);
525 return pmem_attach_disk(dev
, ndns
);
527 ret
= devm_namespace_enable(dev
, ndns
, nd_info_block_reserve());
531 ret
= nd_btt_probe(dev
, ndns
);
536 * We have two failure conditions here, there is no
537 * info reserver block or we found a valid info reserve block
538 * but failed to initialize the pfn superblock.
540 * For the first case consider namespace as a raw pmem namespace
543 * For the latter, consider this a success and advance the namespace
546 ret
= nd_pfn_probe(dev
, ndns
);
549 else if (ret
== -EOPNOTSUPP
)
552 ret
= nd_dax_probe(dev
, ndns
);
555 else if (ret
== -EOPNOTSUPP
)
558 /* probe complete, attach handles namespace enabling */
559 devm_namespace_disable(dev
, ndns
);
561 return pmem_attach_disk(dev
, ndns
);
564 static int nd_pmem_remove(struct device
*dev
)
566 struct pmem_device
*pmem
= dev_get_drvdata(dev
);
569 nvdimm_namespace_detach_btt(to_nd_btt(dev
));
572 * Note, this assumes nd_device_lock() context to not
573 * race nd_pmem_notify()
575 sysfs_put(pmem
->bb_state
);
576 pmem
->bb_state
= NULL
;
578 nvdimm_flush(to_nd_region(dev
->parent
), NULL
);
583 static void nd_pmem_shutdown(struct device
*dev
)
585 nvdimm_flush(to_nd_region(dev
->parent
), NULL
);
588 static void nd_pmem_notify(struct device
*dev
, enum nvdimm_event event
)
590 struct nd_region
*nd_region
;
591 resource_size_t offset
= 0, end_trunc
= 0;
592 struct nd_namespace_common
*ndns
;
593 struct nd_namespace_io
*nsio
;
595 struct badblocks
*bb
;
596 struct kernfs_node
*bb_state
;
598 if (event
!= NVDIMM_REVALIDATE_POISON
)
601 if (is_nd_btt(dev
)) {
602 struct nd_btt
*nd_btt
= to_nd_btt(dev
);
605 nd_region
= to_nd_region(ndns
->dev
.parent
);
606 nsio
= to_nd_namespace_io(&ndns
->dev
);
610 struct pmem_device
*pmem
= dev_get_drvdata(dev
);
612 nd_region
= to_region(pmem
);
614 bb_state
= pmem
->bb_state
;
616 if (is_nd_pfn(dev
)) {
617 struct nd_pfn
*nd_pfn
= to_nd_pfn(dev
);
618 struct nd_pfn_sb
*pfn_sb
= nd_pfn
->pfn_sb
;
621 offset
= pmem
->data_offset
+
622 __le32_to_cpu(pfn_sb
->start_pad
);
623 end_trunc
= __le32_to_cpu(pfn_sb
->end_trunc
);
628 nsio
= to_nd_namespace_io(&ndns
->dev
);
631 res
.start
= nsio
->res
.start
+ offset
;
632 res
.end
= nsio
->res
.end
- end_trunc
;
633 nvdimm_badblocks_populate(nd_region
, bb
, &res
);
635 sysfs_notify_dirent(bb_state
);
638 MODULE_ALIAS("pmem");
639 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_IO
);
640 MODULE_ALIAS_ND_DEVICE(ND_DEVICE_NAMESPACE_PMEM
);
641 static struct nd_device_driver nd_pmem_driver
= {
642 .probe
= nd_pmem_probe
,
643 .remove
= nd_pmem_remove
,
644 .notify
= nd_pmem_notify
,
645 .shutdown
= nd_pmem_shutdown
,
649 .type
= ND_DRIVER_NAMESPACE_IO
| ND_DRIVER_NAMESPACE_PMEM
,
652 module_nd_driver(nd_pmem_driver
);
654 MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>");
655 MODULE_LICENSE("GPL v2");